Stellar wind mass loss rates per unit surface area in solar units as a function of the stellar surface X-ray flux for a sample of K- and G-type dwarfs (blue circles, adopted from Wood et al. 2014; Wood 2018). The dashed green line shows a power law relation of the form $\dot{m}\propto f_{\text{X}}^{1.29}$ and the vertical line indicates the wind dividing line. The red star shows our wind mass loss estimate for WASP-121, which we consider a lower limit.